Abstract

Dermatitis caused by penetrating bird schistosome cercariae is an emerging global public health problem. Infections may be prevented by the use of topical formulations that inhibit cercarial skin penetration. We evaluated nine water resistant formulations by exposing treated arms of volunteers to Trichobilharzia szidati cercariae. Six formulations protected from cercarial invasion. However, after immersion of the treated skin in water (2 × 20 min), only two formulations offered full protection: (1) Safe Sea™, a cream protecting against jelly fish, (2) niclosamide in water resistant sun protecting cream formulations at concentrations as low as 0.05%. In an in vitro system Safe Sea™ and a 0.1% niclosamide formulation caused a high damage rate in T. szidati (92% and 99% after 5 min; only niclosamide with lethal effect) but not in Schistosoma mansoni (1% and 72%; both formulations with lethal effect). However, a 1% niclosamide formulation damaged S. mansoni sufficiently (100% after 5 min) and might offer full penetration protection.

Keywords

Dodecanoic Acid Deet Schistosoma Mansoni Penetration Rate Niclosamide

These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

The authors would like to thank Bayer chemicals and Wacker chemicals, Germany, and Dr. G. Steidl for kindly providing us with the agents, the parasitology group of the University of Erlangen-Nuremberg for participating as volunteers and Korinna Kedves for the advice. This work was supported by the Baden-Württembergisches Sozialministerium, by the Deutsche Forschungsgemeinschaft and communities at lake Bodensee, Germany. The experiments comply with the current laws of Germany.